knpMenuBundle问题

I just tried knpLabs MenuBundle

I am not receiving the flag for the current item, I follower the turorial from https://github.com/KnpLabs/KnpMenuBundle/blob/master/Resources/doc/index.md

Here is my code

use Knp\Menu\FactoryInterface;
use Symfony\Component\DependencyInjection\ContainerAware;

class Builder extends ContainerAware
{
  public function mainMenu(FactoryInterface $factory, array $options)
  {
    $menu = $factory->createItem('root');

    $menu->addChild('Innehåll', array('route' => 'Content'));

    $menu->addChild('Skärmlayouter', array('route' => 'Layout'));

    $menu->addChild('Media', array('route' => 'Media'));

    $menu->addChild('Områden & fastigheter', array('route' => 'Container'));

    $menu->addChild('Användare & behörigheter', array('route' => 'UserManagement'));

    return $menu;
  }
}

And here is what it produces:

<ul>
<li class="first">
<a href="/biztv_symfony/web/app_dev.php/Content/">Innehåll</a>        
</li>

<li>
<a href="/biztv_symfony/web/app_dev.php/Layout/">Skärmlayouter</a>        
</li>

<li>
<a href="/biztv_symfony/web/app_dev.php/Media/">Media</a>        
</li>

<li>
<a href="/biztv_symfony/web/app_dev.php/Container/">Områden &amp; fastigheter</a>        
</li>

<li class="last">
<a href="/biztv_symfony/web/app_dev.php/UserManagement/">Användare &amp; behörigheter</a>        
</li>

</ul>

It claims to include the active link flag (by class "current") automatically, that's why I wanted to try this bundle, so I wouldn't have to meddle around coding that part.

Either I am missing a key point, or this documentation that I am following is missing a key part?

You should use setCurrentUri method. Such as:

$menu = $factory->createItem('root');
$menu->setCurrentUri($this->container->get('request')->getRequestUri());